The Great Black Swamp

The Great Black Swamp, Patrick Wensick. Belt Publishing (ISBN: 9781540270108) 2025.

Summary: The swamp lands of northwest Ohio, their drainage and agricultural development, and toxic algae blooms.

I spent four years of my life driving back and forth across what was once known as the Great Black Swamp in northwest Ohio. It is probably the flattest place on earth. One of the towns in the heart of it, Bowling Green, reflects that flatness while ironically actually having a man-made hill that may be the highest point of the area! During growing season, as far as the eye can see, are fields of corn and soybeans growing in some of the richest soil (at least at one time) in the country. Usually, all that separated you from those fields when you drove on county roads were drainage ditches. In fact, those ditches are a major actor in the story Patrick Wensick tells. They served to drain nearly impenetrable swamp land that was subsequently cleared for those farms.

The occasion for Wensink’s book was the 2014 toxic algae bloom in western Lake Erie that rendered the city of Toledo’s water supply undrinkable for three days. A glass of the water could make you very sick or kill you. He describes the no-nonsense way of coping with this environmental disaster on the part of the people that typifies northwest Ohio culture. Those he interviewed didn’t think of it as that big of a deal.

So, he sets out to understand what led to the disaster. As it turns out, those swamps acted as a huge filtration system that kept Lake Erie clean. They also kept people out for a long time. The region was mosquito and malaria-ridden. The mortality rate of early settlers was high. Not only that, without adequate drainage, the first road through the region was a quagmire.

Then, a former ditchdigger with machine shop experience invented a machine that changed everything. James B. Hill invented and prototyped the first automated ditch digging machine in 1893. The Buckeye Traction Ditcher changed the face of northwest Ohio. Clearing the trees fed a lumber industry around which a number of small towns sprang up, including the author’s home town of Deshler. (Wensick even devotes a chapter to the town’s history including a girl’s poster saying “bring us together” that Richard Nixon and campaign aides saw on a whistlestop in the town and used to turn around his 1968 presidential campaign.)

He traces the agricultural history, including the high-yield production technology that defined the region. But it was also that technology, including fertilizers with nitrogen and phosphorus that led to Lake Erie’s algal blooms. During heavy rains, runoff went into those drainage ditches, all part of the Maumee River watershed, flowing into Lake Erie in Toledo. And the disappearance of all those swamps meant the loss of a filtration system.

Wensink tells that story through onsite interviews with everyone from Toledoans hanging out at Tony Packo’s to the conservation manager for the Black Swamp Conservancy. The latter is an effort to restore swamp habitats throughout the region. At this point, the effort is small. It does not make an appreciable difference in Lake Erie. But places like Bell Woods serve as learning labs for understanding swamp ecosystems. Wensick comes ill-prepared for the mucky and buggy landscape. He also frames much of the narrative with The Story of the Great Black Swamp, a VHS recording of a public television production narrated by Glen Colerider. He found the tape in the library at Bowling Green State university, where he did much of his research.

The account is highly readable, more memoir than dry history. However, as memoir, he also makes the choice to weave in the deterioration of his marriage during his research. The subtitle actually parallels toxic algae and toxic relationships. I wonder about the choice to include this, which I felt distracted from the interesting story he tells about northwest Ohio. Much as this might foster a connection with the author, I just didn’t think it added to his fascinating account.

After describing cuts to environmental efforts at the beginning of the current administration, he concludes with one more visit to the largest remnant of the Black Swamp. Better prepared, he visits Forrest Woods Nature Preserve outside of Defiance, Ohio. He helps dig trenches for a salamander fence, to help monitor the health of the population. A water-covered depression called “The Bowl” is the closest approximation to what the Swamp was like. Implicitly, he ends on a hopeful note, describing the slow, methodical work being done to restore habitats.

All in all, it’s a fascinating narrative combining history and science reporting with eyewitness accounts. It brought new understanding to me, having lived in and traveled this country. But more than this, it helps us understand a problem far more widespread than just the Lake Erie watershed. These blooms occur throughout the world, coinciding in many cases with the drainage of wetlands and swamplands. It gestures toward a way forward, if we act on our understanding of these ecosystems.